System identification modeling of a small-scale unmanned rotorcraft for flight control design

This paper describes the development of a parameterized model for a small-scale unmanned helicopter (Yamaha R-50 with 10 ft rotor diameter) and its identification using a frequency domain identification technique. The model explicitly accounts for the stabilizer bar, which has a strong influence on the flight dynamics characteristics. The accuracy of the identified model is verified by comparing the model-predicted responses with the responses collected during flight experiments. Furthermore, the values of key identified parameters are compared with the values predicted by helicopter theory to show that the model has a physically meaningful parameterization. Both hover and cruise flight conditions are examined.